AWESOME IS NEWSOM

I have no idea how old Joanna Newsom is. Okay, she’s 28. But on her new album, “Have One on Me,” she could be a young girl relating Grimm fairy tales or a middle-aged mother crooning eerie lullabies, or an ageless siren casting spells and howling incantations. Whichever you pin her as, Newsom makes for a compelling storyteller.

Accompanying herself on the harp, an old-fashioned instrument by any means, Newsom modulates her voice in the style of ’70s folk sweetheart Joni Mitchell or modern indie darling Dirty Projectors’s vocalists Amber Coffman, Angel Deradoorian and Haley Dekl. Her literary lyrics (think the Decemberists) spin tales of adventure and romance — horse thieves keep company with whores with black hearts and city girls done up in ribbons and sashes. The whole effect is something vaguely medieval, and thoroughly bewitching.

You get the sense that Newsom was that girl always scribbling in a notebook, who might copy a passage from an illuminated manuscript alongside a list of the names of poisonous mushrooms that grow in the closest forest. Classical allusions, Bible verses, and children’s stories all make their way into her songs, where mythological and contemporary imagery receive equal treatment. Conflict, for Newsom, could be “the war between St. George and the dragon,” or “something caught on a barbed-wire fence.”

But Newsom tempers her bookish inclination with musical audacity — in “Good Intentions Paving Company,” one of the most up-beat songs on the album, she manages a successful drawl and twang that adds a liveliness and vitality to her erudition. Swooping and dipping melodies don’t let the album drag or grow tiresome.

And for the most part, Newsom’s poetic without being too pedantic. The mouthfuls “gormless and brakeless, gravel-loose” and “obstinate as obsidian” stick in my head especially, from the song “Kingfisher.” Then again, I had to look up the word “gormless” (British slang for “lacking intelligence”), so I’ll stop short of saying Newsom can’t be arcane or obscure.

The singer-songwriter’s voice takes some getting used to for a first-time listener — she might initially come across as cracked or strained. But Newsom has a confidence and deliberate way about her that wins an open-minded listener over. And soon every too-high note and syncopated hiccup seems intentional, effortless, and necessary. She’s captivating, and just temperamental enough. Occasionally, when she shows her lightest, softest side (such as in “Esme”), a song threatens to float away, but her jazzier, darker side gives the album weight.

The song “’81” has a melody one could hum along with on maybe the third listen, for instance. But taking in the whole of “Have One on Me” definitely requires some patience. Half of the album’s eighteen songs are longer than seven minutes. That still makes it less dense than Newsom’s second album, the unpronounceable “Ys,” but much heftier than her first, sparer album, “Milk-Eyed Mender.”

“Have One on Me” has less bite and sharp wit than Newsom’s first album, which also seemed more charged and frenetic. On “Milk-Eyed Mender,” Newsom was hungrier and the risks she took had more dare and thrill. I believed her when she sang (in the song “En Gallup”), “Never draw so close to the heat that you forget that you must eat.” They were lines and musical arrangements you could sink your teeth into.

Now that Newsom is more established, she seems to have slowed down and gotten more comfortable. Haunting, drawn-out songs have replaced shorter, more unpredictable ones. Hopefully, though, she won’t get weighed down by ornamentation (the extra instruments and accompanying vocals that occasionally make their way into “Have One on Me,” for instance), but stick to her reliable, traditional harp and her most potent, timeless instrument: her voice.